Device for tapping supply lines



March 3, 1931. K' ETZRQDT 1,794,679

DEVICE FOR TAPPING SUPPLY- LINES Filed May 23 1 950 INVENTOR v KARL ETZRODT ATTO-RNEY Patented Mar. 3, 1931 UNITE-D STATES PATENT OFFICE KARL ETZRODT; OF BERLIN-SIEM'ENSSTADT, GERMANY, ASSIGNOR TO .SIEMENS,-& HALSKE AKTIENGESEL'LSCHAFT, OF SIEMENSSTADT, NEAR BERLIN, GERMANY, A

CORPORATION OF GERMANY DEVICE FOR TAPPIN G SUPPLY LINES Application filed May 23, 1530, Serial No. 455,003,am1 in Germany April 13, 1929.

1 his invention relates broadly to a constant current arrangement and morespecifically to the use of hydrogen-iron resistances for maintaining the current in line tapping devices constant. According to one proposal the hydrogen-iron resistancemay be connected in the lead to the primary winding so that the variations of the line have no influence on the device or the circuits fed by the latter, in particular the heating circuits of hot cathode tubes. However, as is well known, different alternating current supply lines carry different voltages, as for instance 110 or 220 volt. In order not to necessitate the keeping of a stock of transformers for these different line connecting apparatuses for each of these possible voltage values, their primary winding is subdivided in the manner that 110 volt as well as 220 v. may be connected to the transformer whereby the delivered secondary voltage remains the same. Furthermore such line tap devices are equipped in the manner that the current required for the feeding of the cathodes of the rectifier tube or of the amplifier tubes is not directly taken from the line tapping transformer, but is first conveyed from the secondary side of this trans former to a second heating transformer wherein is accomplished the reduction to the required heating voltage, or heating voltages.

If it is desired to use in such line tapping devices with double transformation a hydrogen-iron resistance in the usual manner, that is, in the primary circuit, for maintaining the constancy of the current the necessity arises to keep in stock hydrogeniron resistances for various line voltages. It is an object of this invention to eliminate this disadvantage by connecting the hydrogen-iron resistance in the connecting line between the two transformer stages. This connecting line always carries a uniform voltage regardless of wiether the tapped line has 110 or 220 volts. It is thus seen that with the arrangement described herein only a single type of hydrogen-iron resistances is made'use of. This arrangement has the further advantage that with the tapping of different heating voltages from the heating transformer proper, only one hydrogen-won resistance is required as compared to a plurality corresponding to the cathodes to'be heated.

The invention is represented in the drawing the single figure of which shows diagrammat-ically a preferred embodiment of the in-- 65 vention.

- The line tapping transformer T is provided with a symmetrically sub-divided primary coil of four parts a a a and (a. The secondary 6 leads through ahydrogen-iron resistance 0 to the primary (Z ofthe heating transformer Th. The heating transformer is provided with two secondary coils of which the one (Z, is used for feeding the cathodes of the rectifier tubes e, 6 The other secondary (Z may be employed for feeding the cathodes of amplifier tubes which are to be operated with the line tapping apparatus. The plates of'the rectifier tube are connected to a second ary coil f of the line tapping transformer T, 379 from whose mid-point the one line 9 leads to the steadying circuit, consisting of choke coil-resistances and condensers, and from there to the utilization apparatus. The second line is branched oif from the connect- 5 ing line between the two cathodes of the mentioned rectifier tube.

While the invention is shown as applied to a full Wave rectifying arrangement it is obvious that any type of rectification systom may be used such as a half wave rectifier or a single. tube full wave rectifier and that any such adaptationsare clearly within the scope of the appended claims.

Claims: I

1. In a device of the kind described, rectifying devices having anodes and hot cathodes, an input transformer having means for allowing said system to be connected to any one of a plurality of different line volt ages without changing the voltage across the secondary winding thereof, said secondary winding being adapted to maintain said anodes at proper potentials with respect to said cathodes, an auxiliary secondary wind- 9 ing and a voltage regulating device, a sec ond transformer having a secondary winding thereof adapted to energize the cathodes of the rectifying devices, the primary circuit thereof, said auxiliary secondary wind- 0 ing and said voltage regulating device being connected in series so as to form an electrical circuit and an auxiliary secondary winding for said second named transformer for supplying energy to a load; 2. In a rectifying system utilizing at leastone rectifying device comprising an anode and a hot cathode, an input transformer having a plurality of primary windings and a secondary winding, said secondary winding being connected across the anode and cathode of'said rectifying device, an auxiliary secondary windinga voltage regulating device, said primary winding being adapted to allow said system to be connected to anyone ofra plurality of different line voltageswithout changing' the voltage across said secondary, a second transformer, a secondary winding thereof being 'connected across the cathode of the rectifying device, the primary circuit thereof forming a series circuit with the said auxiliary secondary-Winding and said voltage regulator, and, an auxiliary secondary winding for said second named transformer; a

3. Ina rectifying system, comprising in combination, rectifying devices having an odes and hot cathodes, an inputtransformer having means for allowing said system to be connected to any one of a plurality of different line voltages without changing the voltage across the secondary winding thereof, said secondary winding being connected across the anodes and cathodes ofsaid rectifying devices, an auxiliary secondary winding for said transformer, a second transformer having a secondary winding thereof connectedfacross the cathodes of the rectifying devices for heating same, a voltage regulating device, the primary circuit of said second transformer, said auxiliary secondary winding and said voltage regulati-ng device being connected in series so a as to form an electrical circuit and an auxiliary secondary winding ,for said second named transformer for supplying energy to a load. I a a 4.1m a rectifying system utilizing atleast one rectifyingdevice having an anode and a hot cathode, an input transformer having a primary winding and'a secondary wind- 1 ing, said secondary winding being connected in series with a load and across the anode and cathode of said rectifying device, an auxiliary secondary Winding, a voltage'regulating device, asecond transformer, a secondary winding thereof being 1 connected across the cathode of the rectifying device, the primary circuit thereof forming a series electrical circuit with said auxiliary secondary Winding and said voltage regulating device, and an auxiliary secondary winding for said second named transformer for. sup plying energy to a load circuit.

e- 5. In a device of the kind described, rectifying means having anodes and hot cathv odes, an input transformer having means for allowing said system to be'connected to any one of a plurality of .diflerent'line voltages without changingthe voltage acrossthe secondary winding-thereof, an auxiliary secondary winding for said transformer, a second transformer having a secondary winding thereof connected across'the cathodes of the rectifyingdevices for supplying energy thereto, a'voltage regulator, the primary circuit of said second transformer, said auxiliary secondary winding and said voltage regulator beingrconnected in series so .as to form an electrical circuit and an auxiliary secondary winding for said second named transformer for supplying energy to a load. V i

In testimony whereof I aflix my signature.

" V KARL ETZRODT. 

